Sounds pretty unethical, something that a legit ICO would not dare touch with a 20 foot pole. Imagine a serious team getting caught doing business with someone who will use multiple accounts to create FAKE buzz about their ICO, so that the people who reads this fake hype will be duped into investing into this ICO.
I thought everyone is using promotion services now. A lot of noise among which it is easy to get lost. I think it's quite normal to do promotion on bitcointalk, facebook, twitter, Reddit, telegram and even medium and steemit.